Piston



1, 1936. Q M. A. BECKMANN PISTON Filed June '7, 1929 l I Z0 M Z0Patented July- 1, 1930 NIT-ED STAES PATENT oF- icE MELBOURNE A.IBECKIIANN, OF CINCINNATI, OHIO, ASSIGNOR 'IO HARRY e F CINCINNATI, OHIOa. EATER,

:ers'ron Application filed June 7, 1929. serial No. 369,131.

My invention relates to improvements in pistons and more particularly topistons adapted for use in internal combustion engines. a n

An important object of my invention is the provision of a piston capableof being formed from light weight material such as aluminum, aluminumalloys, magnesium and similar metals in which the undesirable expansionof the piston caused by the relatively high thermal expansion ratio ofthe light wei ht material is rendered comparatively ine ective for allpractical purposes.

A further object of my invention is the production of apiston soconstructed that the heat of combustion, which causes undesirableexpansion of the piston skirt, is so diverted and impeded in the courseofv its transmission from the -head of the piston to its skirt, that itsinfluence upon the skirt of the piston is reduced to a minimum.

Another object of my invention is to provide a piston, the constructionof which will counteract the thrust forces accruing from the explosionon the head of the piston.

A further object of my invention is to control expansion of the pistonso that it will work efiiciently at all operating temperatures. i 5

Other objects and advantages of my invention will be apparent during thecourse of the following description.

opposite side Figure 3 is a vertical sectional view on theline 3-3 ofFigure 1,

Fi ure 4is a horizoptal sectional view on the line 44 of Figure 1, and

cumferentially extending opening 14:. The

piston skirt is relieved by being completely cut away at diametricallyopposite points, and said cutaway portions 15 and 16 extend from pointsspaced from the bottom of the skirt to the opening 14.

Piston pin receiving hubs or bosses 17 and 18 are arranged in thecutaway portions. 15 and 16 respectively and are located substantiallycentrally thereof. The hubs 17 and 18 are provided with the usualbores19. The outer end of the hub 17 is connected to the portions of theskirt at the sides of the cutaway portion 15 by means of a transverse orhorizontal strut 20 arranged'abovethe center of the hub and integrallyformed therewith,- and with the piston skirt. The outer face of thestrut 20 1s flush with the outer face of the hub 17 and the ends ofthestrut 20 have a curvature conformin to the curvature of the adjacentskirt portions and form a continuation thereof, as at 21. A verticalstrut 22 connects the outer end of the hub 17 with the portion of theskirt at the bottom of'the cutaway portion 15 and is arranged centrallyof the cutaway portions and of the hub. The struts 20 and 22 form aT-shaped connection between the outer end of the hub 17' and the pistonskirt with the hub arranged at the juncture of the arms of the T.

The inner end of the hub 17 is connected to the head of the piston bymeans of a vertically extending strut 23 arranged centrally of thecutaway portion 15 and outwardl ofiset at its upper end tojoin'thechead. suitable reinforcing rib 24 connects the hub with thehead and extends down the center of the strut 23. The strut 23 extends ashort distance below the hub 17 and connects with a transverse strut 25whichis joined at its ends to the sides of the piston skirt adjacent thelower end of the cutaway portion15. A Suitable reinforcement rib 26extends from the center of the hub. 17 to the lower end of the strut 25.The strut 23 merges into an encircling flange 27 on the hub 17 andtoet-herwith the strut forms an inverted -shaped connection between thehead, pis

ton pin hub and skirt.

It willbe seen then, that the hub 17 is joined at its outer end to theskirt by the struts 20 and 22, and joined at its inner end to the headand skirt by the struts 23 and 25. At a suitable position between theouter struts 20 and 22 and the inner strut 23 there is an opening 28dividing the. inner end of the hub 17 from the outer end thereof, and

said opening 28 may be out after the piston is cast, but is preferablycast with the piston. When cast with the piston the opening 20 is formedslightly wider at its lower end than at its upper end to facilitateremoval of the pendent of the struts 23 and 25, and heat passing fromthe head 10 through the strut 23 will not be conducted to the struts 20and 22 and the adjoining skirt portions.

v .The hub 18 is connected to the head of the piston by a verticallyarranged strut 23 which extends below the hub and joins with atransversestrut 25 which is joined at its ends to the sides of the piston skirtadjacent the lower end of the cutaway portion 16. The strut 23' mergesinto an encircling flange 27' on the hub 18 and a suitable reinforcing.rib 24' connects the head with the hub 18 and extends down the insideof the strut 23. The struts 23 and 25' have the same position relativeto the hub 18 as the struts 23 and 25 have to the hub 17, and transversestruts 20 connect the strut 23 with the portions of the skirt at thesides of the cutaway portion 16. The struts 20 are oifset outwardly tomerge with the skirt at the edge of 'the cutaway portion 16. The hub 18is not split as is the'hub 17 but is unbroken, and supported by thestruts 20, 23 and 25.

A suitable reinforcement such as 22 may be provided at the lower end ofthe cutaway portion 16, if desired.

The non-thrust side of the piston skirt is provided with a vertical slit29 extending from the bottom of'the skirt to the opening 14 whichseparates the head from the skirt, and the thrust side of the skirt isunbroken.

A substantially continuous annular bearing surface is, therefore,provided adjacent the bottom of the skirt and is unbroken except for thesingle slit 29. The inner portion of the skirt adjacent the slit 25 isprovided with reinforcements 30 which parallel the slit and strengthenthe separated portions of the skirt. While the slit 29 completelyseparates the non-thrust side of the skirt, the arrangement of thetransverse struts 20, 20, 25 and 25 is sufficient to hold the separatedportions of the skirt in position.

In the operation of my improved piston, the head portion is subjected todirect heat generated by the explosion ofgases in the combustionchamber, and this heat is conducted away through the integrallyconnected struts 23 and 23 and through the surrounding metal of thecylinder. The struts 23 and 23 are the only portions of the pistonhaving direct connection with the head, and the only path by which heatmay be conducted to the piston skirt. The heat is'so reduced when itreaches the bottom of the skirt that it is comparatively ineffective dueto the long and circuitous route which it must travel. While the opening28 in the split hub 17 prevents the travel of the heat directly to theside portions of the skirt, the strut arrangement on the opposite sideof the piston is such as to effectively counteract the thrust forcesaccruing from the explosion on the head of the piston.

While I have shown and described the preferred embodiment of myinvention it is to be understood that various changes in the size, shapeand arrangement of parts may be resorted to without departing from thespirit of my invention or the scope of the subjoined 'claims.

Having thus described my invention What I claim and desire to protect byLetters Patent is:

1. A piston comprising a head and skirt,

said skirt having a cutaway portion therein spaced from the bottomthereof, a piston pin hub arranged in said cutaway portion, 'a strutconnecting the outer end of said hub with the portion of the skirt atthe sides of the cutaway portion, the ends of said strut having acurvature corresponding to the curvature of the piston skirt and forminga continuation thereof.

2. A piston comprising a head and skirt, said skirt being spaced fromsaid head by a circumferentially extending opening, saidskirt beingprovided with a cutaway portion 1 extending from a point spaced from thebottom of said skirt into the circumferential opening, a piston pin hubarranged in said cutaway portion, and a transversestrut connecting theouter end of said hub with the portions of the skirt at the sides of thecutaway portion, the outer face of the strut adjacent its ends having acurvature conforming to and spaced from the sides thereof, and atransverse strut connecting said hub with the portions of the skirt atthe sides of the cutaway portion, the outer face of the strut beingflush with the outer face of the hub and having a curvature at its endsconforming to the curvature'of the skirt and forming a continuationthereof.

4. A piston comprising a headand skirt, said skirt being spaced from thehead by a circumferentially extending opening, said skirt being providedwith a cutawayportion extending from a point spaced from the bottomthereof into the circumferential opening,

' a piston pinhub arranged in the cutaway portion and spaced from thesides thereof, a transverse strut connecting said hub with the portionsof the skirt at the sides of the cutaway portion, the outer face of thestrut be ing flush with the outer face of the hub and having a curvatureat its ends conforming to .the curvature of the skirt and forming acontinuation thereof, and a strut connecting the piston pin hub to theportion of the skirt at the lower end of the cutaway portion.

5. A piston comprising a head and skirt, said skirt having cutawayportions therein spaced from the, bottom thereof, a piston pin hubofintegral construction arranged inone of said cutaway portions, strutsconnecting said hub with the head and skirt of the piston, a piston pinhub in the other cutawayportion, said last named hub being split to formtwo spaced portions, one of said portions being connected by struts totheskirt, and the other of said portions of the hub being connected bystruts with the head and skirt of the piston. 7 I

6. A piston comprising a head and skirt, said skirt having cutawayportions therein spaced from the bottom thereof, a piston pin hub ofintegral construction arranged in one of said cutaway portions, said hubbeing connected by struts to the head and skirt of said piston, a pistonpin hub arranged in the other cutaway portion, said last named hub beingsplit to form spaced portions, a transverse strut connecting the outerportion of said split hub to the portions of the skirt at the sides ofthe cutaway portion, and the inner end of said split hub being connectedby struts with the head and skirt of said piston.

7. A piston comprising a head and skirt, said skirt being separated fromthe head by a circumferential opening, said skirt being provided withcutaway portions extending from a point spaced from the bottom of theskirt into the circumferential opening, a pis ton pin hub arranged inone of said cut- 8. A piston comprising a headand skirt,

said skirt being separated from the headby a circumferentially extendingopening, said skirt being provided with diametrically oopposed cutawayportions extending from the circumferential opening to a point spacedfrom the bottom of the skirt, a piston pin hub arranged in one of saidcutaway portions substantially centrally thereof, said hub vbe ing splitto provide spaced portions, a substantially inverted T-shaped strutconnecting the inner portion of said hub'with the head and skirt, asubstantially T-shaped strut connecting-the outer portion of said hub tothe portions of the skirt at the sides and bottom of said cutawayportion, the upper arm of said T-shaped strut having its outer faceflush with the outer face of the piston pin hub and having a curvatureat its ends conforming to the-curvature of the piston skirt and forminga continuation thereof, a piston pin hub of said skirt being separatedfrom the head by a circumferentially extending'opening, said skirt beingprovided with diametrically opposed cutaway portions extending from thecircumferential opening to a point, spaced from the bottom of the skirt,a piston pin hub arranged in one ofsaid cutaway portions substantiallycentrally thereof, said hub being split to provide spaced portions, .asubstantially inverted T-shaped strut connecting the inner portionofsaidhub with the head and skirt, a substantially T-shaped strutconnecting the outer portion of said hub to the portions of the skirt atthe sides and bottom of said cutaway portion, the upper arm of saidT-shaped strut having its outer face flush with the outer face. of thepiston pin hub and having a curvature at its ends conforming to thecurvature of the piston skirt andformof integral construction arrangedin the other cutaway portion, said integral hub being connected bystruts with the head and skirt of the piston, said skirt being providedon its nonthrust side with a substantially vertically arintegralconstruction arranged in the other 12: ing a continuation thereof,a-piston pin hub circumferential opening, said skirt being provided witha cutaway portion extending from the circumferential opening to a pointspaced from the bottom of the skirt, a piston pin hub 5 arranged in saidcutaway portion, said hub being split to provide spaced portions, asubstantially inverted T-shaped strut connecting 'the' inner'portion ofsaid hub with the head v and skirt, a substantially T-shaped strutconnecting the outer portion of the hub to the portions of the skirt atthe sides and bottom of the cutaway portion, the upper arm of said lastnamed T-shaped strut having its outer face flush with the outer face ofthe piston Fin hub and having a curvature at its end, I

con orming to the curvature of the piston skirt and forming acontinuation thereof.

In testimony whereof I afiix m signature.

MELBOURNE A. BEG NN.

